Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.26 (invertase)
 4,927 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Recent studies suggest the importance of two transcription factors, Cdx-2 and NF-LPH-1, in the regulation of sucrase-isomaltase (SI) and lactase-phlorizin hydrolase (LPH) gene expression, respectively. Cdx-2 accounts for the tissue specificity of sucrase expression (16), and NF-LPH-1 varies with postnatal changes in lactase activity, suggesting a role in its developmental regulation (22). We used electrophoretic mobility shift assays to study the relationship of Cdx-2 and NF-LPH-1 to SI and LPH gene expression in Caco-2 cells to provide evidence regarding the role of these factors in the development of sucrase and lactase with cellular differentiation. We found that Cdx-2 levels correlated with SI expression and that NF-LPH-1 did not correlate with LPH expression. These studies suggest a role for Cdx-2 but not for NF-LPH-1 in the development of carbohydrase expression in these cells.
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PMID:Regulation of sucrase and lactase in Caco-2 cells: relationship to nuclear factors SIF-1 and NF-LPH-1. 889 92

Lactase-phlorizin hydrolase (LPH) and sucrase-isomaltase (SI) are intestinal microvillus membrane hydrolases that play important roles in carbohydrate digestion. Although the expression of these enzymes during postnatal development has been characterized, the effect of old age on disaccharidase activity is poorly understood. In the present investigation, we examined the effect of aging on lactase and sucrase activities and their mRNA levels in the small intestines of 3-, 12- and 24- mo-old rats by sampling from nine equidistant segments of small intestine. Total intestinal disaccharidase activity or mRNA abundance was determined from areas under the proximal-to-distal curves. Rats 24 mo of age had total intestinal lactase and sucrase activities that were 12 and 38% lower, respectively, than the 3-mo-old animals (P < 0.05). In contrast, total LPH and SI mRNA abundance did not change significantly. Thus, total intestinal lactase and sucrase activities decrease with age in a manner that likely involves a posttranscriptional process. The age-related decline in disaccharidase activity, if extrapolated to humans, may have important implications for the digestion of carbohydrate contained in the diet of the elderly.
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PMID:Total intestinal lactase and sucrase activities are reduced in aged rats. 920 95

The small intestine matures from a primitive tube into morphologically and functionally distinct regions during gut development. Maximal expression of the genes encoding the digestive enzymes lactase-phlorizin hydrolase and sucrase-isomaltase is spatially restricted to distinct segments along the anterior-posterior axis of the small intestine and is temporally regulated during postnatal maturation. Transcription factors capable of interacting with the intestinal lactase and sucrase gene promoters are candidate regulators of spatio-temporal patterning during gut development and maturation. We aimed to quantitatively examine and compare the relative expression levels of a set of intestine-specific transcription factors along the anterior-posterior gut axis during postnatal maturation. Our analysis was focused on the transcription factors capable of regulating the intestinal lactase and sucrase-isomaltase genes. A real-time PCR protocol was used to quantitatively examine and compare spatially and temporally the relative transcript abundance levels for intestine-specific factors during postnatal intestinal maturation. Distinct spatial expressions patterns were detected along the length of the small intestine for PDX-1, Cdx-2, GATA-4, GATA-5, GATA-6, HNF-1alpha, HNF-1beta and CDP transcription factor genes. There is a general decline in transcript abundance for the factor genes during postnatal maturation. Defining the spatio-temporal expression patterns for intestine-specific transcription factor genes contributes to investigation of the roles that factor gradients play in mediating gut development and differentiation.
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PMID:Spatio-temporal patterns of intestine-specific transcription factor expression during postnatal mouse gut development. 1637 57

It is postulated that dietary carbohydrates and thyroid hormones are major regulators for expression of the lactase/phlorizin hydrolase (LPH) gene in rat jejunum. In this study, we investigated the effects of thyroid hormones and dietary sucrose on LPH gene expression and lactase activity in starved rats. Firstly, animals at 8 wk of age were fed a low-starch diet (5.5% energy as cornstarch) or high-starch diet (71% energy as cornstarch) for 7 d (experiment 1). The mRNA level of LPH as well as lactase activity significantly decreased in rats fed the low-starch diet as compared to those fed the high-starch diet. To investigate the effects of thyroid hormone status, the animals previously fed the low-starch diet were starved for 3 d, and half of the animals were given intraperitoneal (i.p.) injections of 20 microg/ 100 g body weight triiodothyronine (T3) twice daily (experiment 2). The LPH mRNA level and lactase activity were elevated by starvation for 3 d, but they were repressed by the injection of T3 during starvation. To investigate the effects of dietary sucrose in starved rats, they were force-fed a sucrose diet for 6 h (experiment 3). The LPH gene expression and lactase activity were up-regulated by force-feeding a sucrose diet, only when the animals were kept in euthyroid status by daily T3 administrations. In contrast, the sucrase-isomaltase mRNA levels and sucrase activity were unaffected by force-feeding the sucrose diet for both T3-treated and untreated starved rats. Our work suggests that dietary sucrose is capable of enhancing lactase gene expression in starved rats when they have a sustainable thyroid hormone level.
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PMID:Dietary sucrose enhances intestinal lactase gene expression in euthyroid rats. 1719 Jan 5


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